The present disclosure is generally directed to methods and apparatus to exchange a fluid of an implantable device.
Implantable devices can be used to provide a therapeutic agent to one or more portions of a body of a patient. The implantable device may have a chamber for storing the therapeutic agent, and the agent can be released into the patient to provide a therapeutic benefit. After an amount of time, the amount of fluid release can be less than ideal, and the fluid of the implantable device may be replaced, refilled, or exchanged to provide additional amounts of therapeutic agent to extend the therapy.
Work in relation to embodiments of the present disclosure indicates that the prior methods and apparatus to place a fluid in a device implanted in the body can be less than ideal in at least some instances. For example, the amount of therapeutic fluid placed in an implanted therapeutic device with injection can be less than ideal in at least some instances. The therapeutic fluid placed in the implantable device may mix with a fluid already present in the implantable device, such that the amount of therapeutic fluid placed in the implantable devices can be less than ideal in at least some instances. Also, mixing of the implantable device fluid with the therapeutic fluid during exchange can provide a less than ideal sample of the fluid from the implantable device in at least some instances. At least some of the prior injections may at least partially damage the implantable device, for example with repeated injection of a needle through a septum. Further, as the implantable device may be small, the amount of pressure within a chamber of the implantable device may substantially exceed atmospheric pressure in order to provide a clinically acceptable amount of time to place the therapeutic fluid in the implanted device. In at least some instances the seal between the injector apparatus and implantable therapeutic device may be absent or inadequate and the exchanged fluids may leak from one or more of the injector apparatus or the implantable device in at least some instances.
Refilling devices implanted in the eye may present additional challenges in at least some instances. At least some of the prior devices implanted in the eye can be small to decrease interference with vision, and the refill port of such devices can be small and the eye can move rapidly in at least some instances. Alignment of the injection apparatus with the refill port of the implanted device can be more difficult than would be ideal in at least some instances.
Work in relation to embodiments suggests that at least some prior injector apparatus may be reused among patients, for example needles, and it may be helpful to limit reuse of the injector apparatus.
At least some of the prior methods and apparatus to diagnose a patient have been less than ideal in at least some respects. In at least some instances, the eye disease may have progressed more than would be ideal. Although tissue can be removed from the patient with a biopsy or vitreous humor removed with a vitreal tap, such procedures can be more invasive than would be ideal. It would be helpful to provide methods and apparatus to obtain a sample from a patient that is less invasive than prior methods and apparatus.